How Do You Calculate the Centripetal Force for a Swinging Mass?

[Instanbul]

Homework Statement

How much force is needed to swing a 4kg mass in a 3m radius horizontal circle so that each cycle takes exactly 2 seconds. Answer is 118N but the problem is how do I get to that...

Homework Equations

V=2Pir/T F=mv^2/r

The Attempt at a Solution

I tried using F=mv^/r one but I got nowhere close my teacher just solves problems without explaining at all and I have no clue how to solve it except find numbers.


Thank you for your time.

 

[rock.freak667]

I one cycle takes 2 seconds, how many cycles are in one second? Hence what is the angular velocity of the bat?

 

[Instanbul]

It doesn't say that's all the info that the problem gives me.

 

[rock.freak667]

It doesn't say that's all the info that the problem gives me.

I am quite sure you can find the the number of cycles in 1 second given, that 1 cycle takes 2 seconds.

 

[Instanbul]

Aren't I looking for the force of the swing?

 

[rock.freak667]

Aren't I looking for the force of the swing?

Yes but you need to get the periodic time to get F.

 

[Instanbul]

Oh I get it now thank you so much.